Actually only May of this year.
I still feel the OP's problem was the Tx batteries. The loss of control and full throttle was the "smoking gun". Failure to correctly set throttle failsafe and then confirm that it is set properly is a big problem with 2.4Ghz radios. I know I'm making an assumption:o, but is a safe one
We just had a nasty incident with a large gasser at our field, the plane was on the runway, when the loose fitting Spektrum conversion module lost contact, the model carreened out of control, fortunatly only the model was damaged.